Stringing pianos



(No Model.)

S. HANSING.

STRINGING PLANOS.

Pa ented May 4, 1886.

UNITED STATES PATENT OFFICE,

SIIGFRIED HANSING, OF BOSTON, MASSACHUSETTS.

STRINGING PIANOS.

SPECIFICATQN forming part of Letters Patent No. 341,603, dated May 4, 1886.

Application filed May 1G, 1885.

To LZZ 'wh/0m it may concern.-

Beit known that l, SIEGERIED HANsING, of the city el' Boston, and State of Massachusetts, have invented a new and Improved PianoForte, of which the following specification is a full, clear, and exact description.

This invention has reference to an improvement in dividing the different portions of the string between the pressnrebar (near the tuning-pin) and the hitch-pin in such a man ner that the nodes and ventral segments of the vibrations formed upon the string by the blow ol' the hammer may be in a certain proportion to each other, so as to establish a greater purity and fullness of tone.

By intonating a string I desire it to be understood that the outer arrangements in connection with the main portion ofthe string will operate upon the latter in such a manner as to produce a fixed number of nodes and ventral segments"7 upon the string by which an exactly calculated aliquot division is obtained.

In order to make my invention perfectly comprehensible, and enable those skilled in the art to malle use ot' the same, I will first give an explanation of the principal features concerning the vibration el' strings and how these vibrations are produced.

Vhen a well-stretched string is made to vi bratc, it forms one or more ventral segments, each oi' which terminates in two nodes, called the resting-nodes. rhe intermediate point of a segment I will call the generatingnode,7 at which place the operating power is produced. For instance, if at this point the string is brought out of its position of rest by picking it with the lfinger or striking it with a hammer, then the string will be divided in two equal half-segments, forming one complete segment and having a restingnode at each end. Contrary to the operating-power, acts the springpower ofthe string, which, from said fixed ends or nodes, gradually causes the vibrations to become rested.

It is the formation of nodes and segments upon a string which I have had particularly in view for my method of intonation. Ac-

cording to how this formation shall take place, it must be carefully determined at what point ol' the string the hammer shall strike the same, and itis well known to pianolnakers that the power and quality of tone (timbre) greatly depends upon this circumstance.

Although Helmholtz, in his theory on musical acoustics, indicated one-'seventh or one ninth the length of the string at which point the hammer-stroke would give the best result of tone-quality, because ofthe removal thereby of the nnharmonious seventh and ninth upper partials, which otherwise very unpleasantly combine with thc balance ot' tone-suhstance containeddn a vibrating string, yet no piano-maker has ever been able to positively ijx the point of liannnci.stroke according to this idea, and at the same time obtain the much promised and indeed desirable results, which, according to my own theory and method of intonation, I trust maybe accomplished.

The failure of a proper intonation heretofore may be explained in the following: The unequal division in itself is objectionable, for the reason that with one-ninth distance, for instance, the hammer-stroke will form a ventral segment of twoninths ofthe length ofthe string, transferring at the same time as many equal segments upon the whole length as twoninths are contained in the same, giving a result of four and one-hall segments. Now, as one-halt' segment cannot possibly vibrate equally with the remaining four whole segments it must immediately destroy the division first formed and cause uncvcnness and impurity of tone. The art of intonating a string properly therefore must have been a secret thus far.

In my opinion and experience it is the tenth part of the string where the hammer-stroke will give an especially beautiful timbre, caused not only by giving the string a number of equal ventral segments, but also by my method ot' arranging those parts of the string which extend beyond its main portion over the sound and resonance bridges, thereby giving greater prominence to the upper partials of the third and fifth.

I will now illustrate what I have explained and what I shall add hereafter, by referring to the accompanying drawings, in which- Figure I represents a top view showing the arrangement of the strings for the middle and lower tones, and Fig. ll represents a front view of the same.

a b represent the whole length of one of the IOO strings x, which is fastened at a to the hitchpin g, and at the other end, b, to the tuningpin B, the latter being inserted in the wrestplank A.

s represents the pressure-bar, H the soundbridge, S the hammer, and E the sound-board.

f represents the point where the hammer S strikes the string w, being the tenth part of the main portion ofthe same.

D represents the resonance-bridge, with its bridge-pins 1. and IL.

F is the iron plate, with its hitch-pins g,the elevated ridge G, and the point l, bearing the strings.

e d, Fig. 2, represent two nodes having a ventral segment between them.

Having now determined the pointf of hammer-stroke at one tenth the length of the string, measuring` from the point d on the sound-bridge H, I will now proceed to show my method of intonating the string to suit the above-mentioned hammer-stroke. The fact can easilybe demonstrated that when the hammer strikes at the pointf, this being the generating node, and one half of the ventral segment being cut offby the sound-bridge H, the other half segment must (because f d is equal tofe) find its termination in the point e. This and thepoint dwill form thetwo nodes of the first segment, and will measure twotenths of the strings length. Through the stroke of the hammer-having formed said measured segment-a series of equal-sized segments in the form of wave-lines, as shown in Fig. 2 in dotted lines, are now transmitted along the whole length of the string, and as one segment is measuring two-tenths there must be five' complete segments contained in the string from the sound-bridge H to the bridge-pin h. This division bri ng'sinto prominence thel upper partial of the third.

A stringis capable of a particularly audible sounding when made to vibrate while touching any of its aliquot divisions, While at any uneven division it will remain silent. Upon this fact must be based the phenomena of the upper partials, also falled harmonics. The following experiment will furnish the proof. Takinga little wooden wedge, and by pressing it somewhat firmly upon the third part77 of the string nearest the sound-bridge H, which part can easily be found without much measurement,by letting the wedge slowly glide back or forward, while at the same time the string is constantly agitated by means of the hammerstroke, when the string begins to sound clear we will then have the fth77 ofthe fundamental tone. A It will now be seen at a glance that instead of the wedge, we can substitute the sound-bridge or an agraffe for dividing the string and letting the usual pressure-bar take the place of the sound-bridge. The string will then respond to the outside agitation just as well as in the experiment with the wedge. Although in practical piano-making it could not occur that a string with an inaccurate division would be completely silent while being struck, because of the firmer support it receives at the sound-bridge than could be well given by the wooden wedge, still it will be suiciently proved by my explanation that such string will not respond with such spontaneity as it does with correct apportionment of the nodal points.77 Notwithstanding that, the pitch of the tone has its origin and emanates from the main portion of thestring, extending from the sound-bridge H to the first bridge-pin, h, of the resonance-bridge D, we must take into consideration that the body of sound extends beyond the soundbridge H to the pressure-bar c. With the same readiness that a string responds in the one-third division, it will also do'so in the division of one-sixth,7 and, as by means of the hammer-stroke the string from the pin h to the sound-bridge H is divided into ve ventral segments, it will be seen that the onesixth division can be obtained by adding one segment from the sound-bridge to the pressure-bar, giving it the full lengths of the other ventral segments.

We will resume the experiment of the little wooden wedge. Having divided the string at one-third its length, we can, without silenc- 'ing the string, subdivide its remaining twothirds again in one-third each. The reason herefor is that when the vibrating string is divided at one third its length it forms immediately three equal ventral segments, the operating power of which exists in the center of the same, while the resting-nodes are one at each end ot' the string and two at onethird and two-thirds distance Vfrom those. Should we now interrupt the vibrating string by pressing it in the center of either one of the three segments, it would immediately become silent, for the reason heretofore explained-that the segment thus divided in two half -segments cannot possibly vibrate with the two remaining whole segments, and must destroy, therefore, the operative power of the whole. This experiment proves, in the first place, that having determined the length of the string from the pressure-bar c to the point d on the sound-bridge, the whole length of the string from c to h will be divided in six equal parts. Vhen the hammer is now made to strike at the point f, the generating-node of the string, the rst segment, e d, being equal to the segment d c, the string will then vibrate in six equal ventral segments. Secondly, having once adopted the length of the string from c to d the hammer must positively strike at the point f, the generatingnode of the first segment d e. Otherwise, should it, for instance, strike the string at e, it would immediately destroy the aptitude of the described equal division, as e in such case would be a generating-node and would form two and one-half segments upon the string, which one-half, together with the one-half segment d c, would form two divided half-segments, which cannot vibrate in harmony with two whole segments. I have therefore adopted IOO IOS

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the rule that the hammer must operate at the point f, the distance from the sound-bridgeH being one-tenth part ol the main portion of the string, and the distance from the soundbridge H (the point d) to the pressure-bar c must be Hdouble as long7 as from the hammer-stroke j to the point Z ou the soundbridge. It will now appear of vast importance that through my method of intonation the unharinonious upper partials of the seventh and ninth will be not only removed, but that, instead, the harmonious upper partials of the third and lil'th are brought into greater prominence. Itis well known that the portion of the string which extends from the bridge-pin i to the point Z on the elevated ridge G of the iron plate F has a particular influence upon tone substance and power, because it stands in direct connection with the resonance like the main portion ol' the string. However, we must not considerthe same as an independent soundbody, but must intonate it, so as to operate most advantageously in assisting the tone substance heretoi'ore obtained.

Experience teaches that objects, such as window-panes, loose metal work, stove-doors, die., will vibrate when a certain tone whose number ol' vibrations are equal to those contained in said objects is brought in contact with the same. Any other tones oi' unlike vibrations, including even the octaves of the l'ormer, have no inlinence upon these objects. In a piano-forte this influence ol' transporting tone-power is of great importance, and becomes more prominent when the dampers are raised from the strings. rthis ci reumstance causes that every string in the instrument which contains the same number ol' vibrations (either as fundamental or partial tones) as the tone which is produced by the stroke ol the hammer will be divided in aliquot parts corresponding to those ol" said single tone, and therefore, through the additional increase of sound, will put the resonance in a state olvl particular activity. Upon this fact l have based. my method of intonating that part of the string which extends from the resonance-bridge pin to the point Z of the iron plate. If the same shall have the desired inlluence, its tone must be contained in the main portion ofthe string as a natural 'ione,7 or, vice versa, the tone .of the main string, may be contained as a natural tone in that of the one to be intonated, as I will hereinafter show. As I have already established the division of the string from the bridgeqiins to the pressure bar, bringingin pre-eminence the upper partials of the third and fifth, it will appear most desirable to intonatie the indicated string beyond the resonance-bridge for the same said upper partials, which, by doing so, will greatly add to the balance ol' tone-substance already obtained. Il" the length of the string from the left-hand bridge-pin to the ridge is one-fifth of the length ol" the string from the right-hand bridge-pin to the sound-bridge, this fraction will produce the third two octavcs higher than the fundamental tone of the main string. Therefore this intonation applies particularly to the longer strings. In the drawings these longer strings are designated as fr', and the bridge-pins, to which these strings are secured, as t" and Zi. Vith these strings m the distance of the string from t" to the ridge Z is one-fifth the distance of the string from the bridge-pins ZL to the sound-bridge H. If the length of the string lZ Z is onethird of the length 71, eZ, then it will produce the iiith one octave higher, and therefore this intonation applies particularly to central strings-that is to say, for the central strings, rv, the distance i Z is Onethird of the distance ZZ (Z. As, however, the upper two oetaves of a piano-forte (not shown in the drawings) do not to any extent acceptable to our ear contain this latter partial of the fifth one octave higher, it becomes necessary to intonate the length of the strings from ridge to left-hand bridge-pin in said two octaves for lower combining tones, as three is in proportion to two. For instance, if the main string is two inches long, the string from the ridge to left-hand bridge-pin must be three inches, or il' the first is three inches the latter must be iour and one-half inches, &c. Thus the relationship of these tones brought in connection by striking the main string with the hammer will cause the above-mentioned activity of the resonance upon all its parts, obtaining thereby not only great tone purity, but also more power of tone.

In order not to waste any part of the string that can accurately be employed for intonation, I have given the remaining string, which is situated between the point Z and the hitchpin g, a similar disposition as that obtained in the string between the sound-bridge H and the pressure-bar o, differing from the latter in this manner. 'When the length of the string between i Z is one fth of the main portion Zz. (Z, then the string Z g must be either one-tenth or one-twentieth of the length of the main string, and when the length Z Z is one-third ofthe main string, then the string Z g must be either onesixth or one-twelfth of the length of the main string.

Being aware that it is not new to have the point of percussion occur :from one-ninth to onecleventh of the string, I do not broadly claim such as of my invention.

I claim as my invention- The combination, in a piano-forte, of strings x, hammer S, sound-bridge H, and bridgepins h, the distance between the point of hammer-stroke and sound-bridge being equal to Onehalf the dist-ance between sound-bridge H and pressurebar c, substantially as specifred.

SIEGFRIED HANSING.

Vitncsses:

JOHN MAY, PAUL Gnnrmnn'r.

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